Case Study: Preventing Site Outages During the Holiday Rush

This time of year, many companies are now in the process of conducting web load testing in advance of the holidays. In this article, you'll learn details on how a large online retailer conducted web load testing in advance of the holiday spike in traffic - and they're moving into the holiday season more confidently than ever.

Why This ‘Retailer' Came to CompuwareAs a leading retailer of personalized gifts, it needed to ensure that its website would be ready for the 2012 holidays. Despite load testing its site last year with a different vendor, The Retailer experienced several outages during peak traffic, costing them significant revenue. Great customer experiences and relationships are very important to this Retailer - both in-store and online. However, as a result of the site outages, customer relationships were impacted both online and in its brick and mortar locations.

In order to provide its customers with great experiences, and protect its reputation, the Retailer's online store has to not only provide a great shopping experience, but also withstand the traffic spikes caused by seasonal upswings, events and promotions. Since performance directly impacts the business, much is riding on the performance of its website during the critical holiday season.

Understandably, leery of promises about ensuring scalability after last years' experience, the Retailer contacted Compuware to engage services to deploy its Gomez 360o Web Load Testing solution which was selected based on three key factors:

Enough Load could be generated from enough locations to thoroughly stress its system;

Real browser technology for the agents would ensure the most realistic testing and problem identification; and

The Retailer utilized Compuware Professional services in order to have an independent third-party that would help them design a test plan to re-create issues, not just prove that the system worked.

With Gomez 360o Web Load Testing, each transaction performed during load testing was traced. In addition, all of the diagnostic information correlated into load test reports so there was complete visibility into how applications behaved under load. Armed with this information, the Retailer identified any problems in both proprietary code as well as third-party code.

Retailer's Plan of Attack

Test from the end-user perspective using last mile, real browsers and less than ideal Internet speeds.

Test the production system during least use in the middle of the night giving a four hour test window with normal peaks lasting approximately 10 hours

Calculate load volume based on highest hourly historical activity - then multiply the test window by 2.5 to obtain a 10 hour peak.

ResultsThe Retailer's site could handle the peak load but not for the allotted four hours. The analysis revealed multiple root causes of instability including:

Load balancer issues

Gateway errors

SQL issues

JVM Issues

Reconfiguring the load balancer solved the site crashes while code changes optimized certain queries. JVM optimization was taken care of by forcing garbage collection more frequently.

The quality and speed of the Retailer's website is now on par to provide exceptional user experiences for their e-commerce customers, aligning it with the caliber of in-store service that is expected. The Retailer was also able to reduce testing iterations and cycle time with proactive problem resolution and prevention and validate that the website architecture is performing properly for maximum scalability under peak load.

Actionable data is easily provided to their outsourced development vendor. This not only gives the vendor a deep, code level view in order to quickly fix and optimize the application code, but relations between the vendor and the retailer are greatly improved since the data eliminates finger pointing.

The Retailer is confident it will not have a repeat of last year's outages and its site will perform optimally during peak traffic periods throughout the holiday season.